Revival of the monsoon on Thursday will bring down rain intensity, and distribution over the North-Eastern States in a known swing of fortunes as the monsoon emerges out of a 'break' phase. These states have made reasonably good gains during this phase except in a few Met subdivisions.
Rain deficits continue in Arunachal Pradesh (-22 per cent) and Nagaland-Manipur-Mizoram-Tripura (-39 per cent) since the monsoon made an onset over Kerala on June 3. East India, especially Bihar, Jharkhand, and West Bengal's plains, have recovered smartly, India Meteorological Department (IMD) said.
Deficits in South, North-West
Deficits in North-West India and the South Peninsula have dragged the rainfall for the country as a whole to -2 per cent (falling within the normal limits as per IMD classification). Lakshadweep (-50 per cent), Kerala (-44 per cent), and Coastal Karnataka witnessed unexpected slippages after the rains shut out.
The monsoon is set to revive from the current 'break' phase over the next two days and may drag in rains to the as-yet uncovered regions, including the national capital. But indications are that it may be until July 18/19 when these regions get just enough rains to bring back day temperatures to normal.
In its outlook on Tuesday, the IMD reiterated that the monsoon might revive gradually over the South Peninsula, including along the West coast and adjoining East-Central India, from today (Wednesday). A low-pressure area will form off the North Andhra Pradesh-South Odisha coasts around Sunday.
Light rains to start with
The latest available 46-day monsoon outlook by the European Centre for Medium-Range Weather Forecasts (ECMWF) revealed as much on Tuesday. It agreed with the IMD outlook for the revival of the monsoon but doubted if any meaningful gains would accrue immediately to Delhi and its surroundings.
Rains would be light to moderate to start with from July 10/11 but may build up in scale a week later to bring the ambient day temperatures to the normal level, the ECMWF outlook said. The IMD indicated the possibility of the odd flare-up over Delhi in between before the activity subsides, in an outlook valid until July 16.
The bugbear of westerly winds over North-West India and an approaching westerly trough may hold back rapid monsoon advancement during the next week, according to an assessment by RMSI, a global GIS consultancy in geospatial technology solutions, modelling and analytics, substantiating the outlook.
Monsoon easterlies from Bay
"So, Delhi and other north-western areas would not see much rain as should normally be the case after the arrival of the monsoon. It would take a fresh pulse to revive the monsoon currents," the consultancy said. The IMD has said that a low-pressure area may form over the Bay of Bengal over the next 4-5 days.
Monsoon easterlies from the 'low' in the Bay of Bengal may fill parts of eastern India from Thursday and spread into North-West India, covering Punjab and North Haryana. Thus, it may enter the remaining parts of West Uttar Pradesh, some more parts of Punjab, Haryana and Rajasthan and Delhi around Saturday.
Rains outlook for N-W India
Scattered to widespread rainfall with isolated heavy falls are forecast over Madhya Pradesh, Vidarbha, Chhattisgarh from Thursday and isolated very heavy over Vidarbha and Chhattisgarh. A similar outlook is valid in North-West India from Friday with isolated heavy rainfall over Uttarakhand from Thursday.
Himachal Pradesh and Uttar Pradesh will start getting their share from Friday and East Rajasthan from Saturday. The reviving monsoon will also scale up rain along the West Coast from Friday. Widespread rain with isolated heavy to very heavy is likely over Konkan, Goa, Coastal Karnataka, Kerala and Mahe.